Do we use foreign keys in Entity Framework?
In this tutorial learn to use the ForeignKey attribute in Entity Framework to configure the Foreign Key Property. We use the Foreign Key to define the relationship between two tables in the database.
What is meant by foreign key in Entity Framework?
The ForeignKey attribute is used to configure a foreign key in the relationship between two entities in EF 6 and EF Core. It overrides the default conventions. As per the default convention, EF makes a property as foreign key property when its name matches with the primary key property of a related entity.
How do I set primary key and foreign key in Entity Framework?
To create Foreign Key, you need to use ForeignKey attribute with specifying the name of the property as parameter. You also need to specify the name of the table which is going to participate in relationship. I mean to say, define the foreign key table.
What is include Entity Framework?
As a performance measure, Include() allows you to indicate which related entities should be read from the database as part of the same query. Excerpt from the linked page: Here are several ways that the Entity Framework can load related data into the navigation properties of an entity: Lazy loading.
How do I join Entity Framework?
Method Syntax First join the first two tables. Employees is the outer table and People is the inner table. Project the properties you want to in the output. Also include those properties, which you want to use in the join condition further down the query.
What does a zero to one relationship look like?
A zero to many optional relationship indicates that a person may have no phone, one phone, or many phones, and that the phone may not be “owned,” but can only be owned by a maximum of one person. A zero to one relationship might indicate that a person may be a programmer, but a programmer must be a person.
What is the foreignkey attribute in Entity Framework Core?
The ForeignKey Attribute. The ForeignKey attribute is used to specify which property is the foreign key in a relationship. In the following example, the AuthorFK property in the Book entity does not follow Entity Framework Core’s convention for foreign key names. Left as it is, Entity Framework Core will create an AuthorFK field…
When to use a foreign key in EF?
It overrides the default conventions. As per the default convention, EF makes a property as foreign key property when its name matches with the primary key property of a related entity. name: Name of the associated navigation property or the name of the associated foreign key (s).
Do you need a foreign key property in dependent entity class?
While it is recommended to have a foreign key property defined in the dependent entity class, it is not required.
Which is an example of a foreign key?
In the following example, the AuthorBiographyId property in the AuthorBiography entity does not follow the Entity Framework convention for foreign key names, and it will create an AuthorId field which it will configure as a foreign key.